The best smart smoke and carbon monoxide detectors of 2026

Rules are set by each province and territory, so check the requirements where you live, including who has to install and maintain alarms in a rental home. Whatever the local rules, the safe approach is a smoke alarm on every storey and outside sleeping areas, plus a CO alarm near the bedrooms if your home has a fuel-burning appliance, such as a gas furnace, boiler, water heater, wood stove or fireplace, or an attached garage. Look for a ULC or CSA mark on any alarm you buy.

Interconnected alarms are better in any home with more than one storey, because they all sound as soon as one detects smoke. Check whether your province or territory requires them; either way, they're worth having. Wireless interconnected alarms with sealed 10-year batteries avoid rewiring. Smart alarms add phone alerts when you're out, but check the certification: look for a ULC or CSA mark, while European models list EN 14604 for smoke or EN 50291 for carbon monoxide.

Put it in the same room as the gas furnace, boiler, water heater, wood stove, fireplace or other fuel-burning appliance, roughly 1 to 3 metres away from it. Mount it high on a wall or on the ceiling as the instructions specify, away from windows, vents, range hoods and exhaust fans. Adding one outside the bedrooms is sensible, especially if a flue runs through them. A CO alarm doesn't replace an annual service of your furnace or boiler by a qualified technician.

Replace smoke alarms every 10 years, or by the date printed on them, because the sensor degrades even if the alarm still sounds. CO alarms typically last 5 to 10 years and give an end-of-life warning. Once a month, hold down each alarm's button until it sounds, vacuum dust from the vents and, on hardwired alarms with a backup battery, replace that battery when it chirps. Write the installation date on each alarm so you know when it's due.

A single chirp every 30 to 60 seconds almost always means a low battery or, on sealed units, that the alarm has reached the end of its life. Replace the battery or the whole alarm. If it goes off while cooking or after a shower, move it farther from the kitchen or bathroom, or install a heat alarm in the kitchen instead. Hardwired alarms that chirp after a power outage may simply need resetting with the hush button.